The present invention relates to a channel estimation method, and more particularly, to a channel estimation method and associated device capable of optimizing the performance of estimating a data channel of a data resource element even if the physical resource block (PRB) bundling information is unknown at the receiver.
In communication systems such as the third Generation Partnership Project (3GPP) Long Term Evolution (LTE) (hereinafter “LTE”), variations in phase and amplitude are introduced into signals transmitted along the channel. These variations can be realized as the channel response. The channel response is usually frequency-dependent and time-dependent. The channel degradation of the received signal can be compensated if the receiver can correctly detect the channel response. Detection of the channel response is called channel estimation. In the LTE system, a number of resource elements (REs) are chosen to carry pilot signals for channel estimation purposes. The pilot signals contain useful information which facilitates the channel estimator to detect the channel response of a specific frequency and time. The resource elements carrying the pilot signals are also called pilot resource elements.
Due to increasing data traffic involved in wireless communication techniques, how to optimize estimation for data channels of the data resource elements has become an important issue. Estimating the data channel of data resource elements (REs) is important for the recovery of the transmitted information data at the receiver, to thereby reach high receiving quality.
In the 3GPP specification, a plurality of neighboring pilot resource elements in the time-frequency domain (e.g. the OFDM system) may be utilized to jointly perform channel estimation for the data resource element in order to improve the channel estimation performance if those pilot resource elements are correlated. The receiver, such as user equipment (UE), may not be able to tell which pilot resource elements that neighbor the data resource element are helpful or correlated, however. How to optimize the channel estimation performance when there is limited information at the receiver is therefore an issue in the field which requires a solution.
There is a need for a novel channel estimation method and associated device to improve the channel estimation performance, to thereby overcome issues existing in the prior art.